The package the seeds came from had no instructions...it was my last years (actually 2 years ago) pumpkin. There is no sign of surface disruption, no digging, piles, pods....
I suspect it is animals, but the seeds aren't being eaten (yet). I hope at least one of them grows, as the garden this year is going to suck due to the crappy weather. I still haven't planted anything other than pumpkin seeds, and they are unplanting themselves. :frowning:
Seriously though, I'm betting on birds. They don't so much dig as scratch and it might be that you don't notice their slight scratches. They might not even be wanting the seeds but are instead looking for insects in the soft and easily scratchable dirt.
You might wish to instead start the seeds in small starter pots and then later set them out as seedlings in the garden.